Conventionally, electric vehicles and hybrid vehicles are provided with a vehicle approach notification sound generating apparatus that generates a pseudo sound (vehicle approach notification sound) in order to make pedestrians recognize approach of an own vehicle, and an example of the apparatus is an apparatus that controls sound quality and a pattern of a vehicle approach notification sound according to a predetermined condition (for example, see Patent Document 1).
In Patent Document 1, sound pressure and sound quality of a pseudo sound are changed based on information acquired from the outside. Further, for example, a pseudo sound of another vehicle that approaches and goes forward is set to be different from a pseudo sound of the own vehicle so that ambient pedestrians is made to easily recognize the presence of the own vehicle.
Further, a technique that changes a pattern of a pseudo sound of an own vehicle so that the pattern is different from a pseudo sound of another vehicle and an ambient sound (for example, see Patent Documents 2 to 5).